W-band radar: an unconventional tool for precipitation studies

Dr. Sergey Matrosov

01 December 2015, 4:00 PM

W-band frequencies at around 90 - 95 GHz are the highest frequencies traditionally used by meteorological research radars. Due to strong attenuation of W-band signals by atmospheric gases and especially by liquid hydrometeors, radars operating in this frequency band have been generally used for studies of non-precipitating clouds at relatively short ranges and mostly in the vertically pointing mode. During the last several years, however, unconventional approaches, which use attenuation as the input information for retrievals, have been developed for quantitative estimations of rain rate from W-band radar measurements. Recently, polarimetrically upgraded, scanning W-band radars also became available for atmospheric research. Depolarization measurements from such radars have been shown to be useful for identifying types of precipitating and non-precipitating ice hydrometeors and estimations of their general shapes (e.g., particle aspect ratios). General approaches used for precipitation rate retrievals and ice hydrometeor shapes estimations utilizing W-band radar measurements will be discussed with an emphasis on the use of the spaceborne W-band cloud profiling radar and Atmospheric Radiation Program’s ground-based scanning polarimetric W-band radars.